Systemic Amyloid A Amyloidosis Secondary to Xanthogranulomatous Pyelonephritis.

The combination of systemic amyloid A (AA) amyloidosis and xanthogranulomatous pyelonephritis (XGP) resulting from a chronic urinary tract infection is extremely rare. We herein report a case of systemic AA amyloidosis secondary to XGP for which clinical remission developed after nephrectomy. To our knowledge, this is the first case report describing the clinical improvement of systemic AA amyloidosis secondary to XGP after nephrectomy in Japan. Clinicians should be aware of this uncommon combination and search for amyloid depositions in cases of XGP.

Pielonefritis xantogranulomatosa: un reto actual para la laparoscopia.

OBJECTIVE: To present the results of our case series on laparoscopic nephrectomy in xanthogranulomatous pyelonephritis (XGP). METHODS: A retrospective study was conducted that included 143 patients treated with laparoscopic nephrectomy for non-functioning kidney, of whom 15 had XGP, within the time frame of 2011 to 2019. The demographic and clinical data were collected, along with the intraoperative results, complications, and days of hospital stay. RESULTS: Transperitoneal laparoscopic nephrectomy was successfully performed on 15 patients with XGP, with no need for conversion. Mean intraoperative time was 124.4 minutes (range 70-240) and intraoperative blood loss was 148.5 ml (range 30-550), with no blood transfusion required. No intraoperative complications occurred but there was one postoperative complication (6.6%), classified as Clavien-Dindo I (surgical wound infection). Mean hospital stay was 2.85 days (range 2-7). CONCLUSIONS: Nephrectomy is the definitive management for XGP, and the laparoscopic approach should be considered a treatment modality, despite the fact that the pathology involves a severe chronic inflammatory process. Its benefits are reduced surgery duration, less blood loss, a lower complication rate, and fewer days of hospital stay, when performed by a skilled and experienced surgeon.

OBJETIVO: Presentar los resultados de nuestra serie de nefrectomía laparoscópica en pielonefritis xantogranulomatosa (PXG). MÉTODO: Se realizó un estudio retrospectivo que incluyó 143 pacientes tratados con nefrectomía laparoscópica por exclusión renal, de los cuales 15 fueron por PXG, en el periodo comprendido de 2011 a 2019. Se recolectaron datos demográficos y clínicos, resultados transoperatorios, complicaciones y días de estancia hospitalaria. RESULTADOS: Se realizó nefrectomía laparoscópica transperitoneal de forma exitosa en 15 pacientes con PXG, sin necesidad de conversión. El tiempo transoperatorio promedio fue de 124.4 minutos (rango: 70-240). El sangrado transoperatorio fue de 148.5 ml (rango: 30-550), sin requerimiento de transfusión sanguínea. No se reportaron complicaciones transoperatorias; se presentó una complicación en el posoperatorio (6.6%) clasificada como Clavien-Dindo I (infección de la herida quirúrgica). La estancia hospitalaria promedio fue de 2.85 días (rango: 2-7). CONCLUSIONES: El manejo definitivo de la PXG es la nefrectomía, y el abordaje laparoscópico debe ser considerado como una modalidad de tratamiento a pesar de ser una patología que presenta un proceso inflamatorio grave y crónico, obteniéndose beneficios como disminución en el tiempo quirúrgico, menor sangrado, menor tasa de complicaciones y menos días de estancia hospitalaria cuando es realizado por un cirujano experimentado.

Lung abscess with chronic cough secondary to xanthogranulomatous pyelonephritis: A rare case report.

RATIONALE: Xanthogranulomatous pyelonephritis (XGPN) is a form of chronic pyelonephritis caused by chronic calculus obstruction and bacterial infection, leading to the destruction of the renal parenchyma and calyces. Conservative treatment is usually not sufficient, and surgical intervention is still the main curative approach. XGPN with transdiaphragmatic extension and lung abscess formation is a rare condition. PATIENT CONCERNS: We report a 64-year-old woman who presented with persistent productive cough. DIAGNOSES: Lung abscess secondary to XPGN. Both nephrostomy urine and sputum cultures showed Proteus mirabilis infection with the same antibiotic sensitivity spectrum, but blood culture was negative. INTERVENTIONS: Laparoscopic radical nephrectomy and prolonged antibiotic treatment. OUTCOMES: The lung abscess and cough gradually resolved in 1 month after nephrectomy. CONCLUSION: Lung abscess secondary to transdiaphragmatic extension of XGPN is rare but should be considered in patients with lower lung infections that are unresponsive to treatment, especially infections due to unusual respiratory pathogens such as P mirabilis.

Perioperative outcomes and risk factors for major complications associated with nephrectomy for Xanthogranulomatous pyelonephritis: a multicenter study.

PURPOSE: To determine the risk factors associated with major complications in patients with histologically confirmed Xanthogranulomatous pyelonephritis (XGP) who underwent nephrectomy. METHODS: A multicenter retrospective study was performed including patients who underwent nephrectomy between 2018 and 2022 with histopathological diagnosis of XGP. Clinical and laboratory parameters at the initial presentation were evaluated. Data on extension of XGP was recorded as per the Malek clinical-radiological classification. Characteristics of nephrectomy and perioperative outcomes were obtained. The primary outcome was major complications, defined as a CD ≥ grade 3 and the need for intensive care unit (ICU) admission. Secondary outcomes included the comparison of complications evaluating the nephrectomy approach (transperitoneal, retroperitoneal, and laparoscopic). A sub-analysis stratifying patients who needed ICU admission and Malek classification was performed. RESULTS: A total of 403 patients from 10 centers were included. Major complications were reported in 98 cases (24.3%), and organ injuries were reported in 58 patients (14.4%), being vascular injuries the most frequent (6.2%). Mortality was reported in 5 cases (1.2%). A quick Sepsis-related Organ Failure Assessment (qSOFA) score ≥ 2, increased creatinine, paranephric extension of disease (Malek stage 3), a positive urine culture, and retroperitoneal approach were independent factors associated with major complications. CONCLUSION: Counseling patients on factors associated with higher surgical complications is quintessential when managing this disease. Clinical-radiological staging, such as the Malek classification may predict the risk of major complications in patients with XGP who will undergo nephrectomy. A transperitoneal open approach may be the next best option when laparoscopic approach is not feasible.

Clear Cell Renal Cell Carcinoma with Immunotherapy Effect Mimicking Xanthogranulomatous Pyelonephritis.

Renal cell carcinoma is now increasingly treated with checkpoint inhibitor therapy, predominantly in the metastatic setting or occasionally in the adjuvant setting; however, there is little published histopathology data demonstrating the post-therapy features of renal cell carcinoma tumor tissue. We report a middle-aged man, who was undergoing treatment with pembrolizumab for locally recurrent cutaneous basal cell carcinoma and was incidentally found to have a renal mass. Radical nephrectomy demonstrated a 5.0 cm renal mass with extensive xanthogranulomatous features, mimicking xanthogranulomatous pyelonephritis. However, rare clusters of cells demonstrated gland-like lumina, clear cytoplasm, and slightly increased atypia, suggesting scant residual renal cell carcinoma cells. Immunohistochemistry demonstrated focal positivity for pan-keratin and keratin 8/18, EMA, PAX8, CD10, and carbonic anhydrase 9 (CA9), supporting a diagnosis of renal cell carcinoma with extensive treatment response, to the point that it mimicked xanthogranulomatous pyelonephritis. This report demonstrates the histologic features of post-immunotherapy renal cell carcinoma, aiding pathologists in recognition of this phenomenon, which may be misdiagnosed as an inflammatory process, if immunotherapy was performed for other reasons.

Perioperative predictors for complications in patients with Xanthogranulomatous Pyelonephritis treated with nephrectomy.

INTRODUCTION: Xanthogranulomatous pyelonephritis is an inflammatory disease characterized by chronic obstruction and infection. This pathology is a life-threatening condition when surgical treatment is carried out. We decided to retrospectively evaluate whether there were perioperative factors that predict complications in patients who undergo nephrectomy. METHODS: We reviewed all nephrectomies done in the period of 2013-2018, in a tertiary referral Hospital with the histopathological diagnosis of Xanthogranulomatous Pyelonephritis. RESULTS: The presence of renal abscess at admission was observed as a risk factor associated with perioperative complications (p = 0.002), presence of abscess was observed in 47.4% of subjects without complications compared to 89.3% of the perioperative complication group. Higher rates of blood transfusion requirement were observed in the perioperative complication group, 89.3% compared to 68.4% (p = 0.029), furthermore, perioperative bleeding was slightly greater in the complication group compared to its counterpart, 700 mL, and 600 mL, respectively (p = 0.01). CONCLUSIONS: Anemia and the presence of abscess were important perioperative factors that predict perioperative complications.

Xanthogranulomatous pyelonephritis: a systematic review of treatment and mortality in more than 1000 cases.

OBJECTIVES: To systematically review the current demographics, treatment and mortality rate associated with xanthogranulomatous pyelonephritis (XGP) and to test the hypothesis that the weighted pooled peri-operative mortality rate will be <10%. METHODS: Searches were performed of the Cochrane, Embase and Medline databases and the grey literature for studies published during the period 1 January 2000 to 30 August 2021. Eligible studies reported cohorts of ≥10 predominantly adult patients with XGP and described either average patient age or mortality rate. RESULTS: In total, 40 eligible studies were identified, representing 1139 patients with XGP. There were 18 deaths, with a weighted pooled peri-operative mortality rate of 1436 per 100 000 patients. The mean age was 49 years, 70% of patients were female and 28% had diabetes mellitus. The left kidney was more commonly affected (60%). Four patients had bilateral XGP, and all of whom survived. Renal or ureteric stones were present in 69% of patients, including 48% with staghorn calculi. Urine culture was positive in 59% of cases. Fistulae were present in 8%. Correct preoperative diagnosis occurred in only 45% of patients. Standard treatment continues to comprise a short cause of antibiotics and open radical (total) nephrectomy. Preoperative decompression occurred in 56% of patients. When considered at all, laparoscopic nephrectomy was performed in 34% of patients. Partial nephrectomy was conducted in 2% of patients. CONCLUSIONS: Xanthogranulomatous pyelonephritis has a lower mortality rate than historically reported. A typical patient is a woman in her fifth or sixth decade of life with urolithiasis. While open radical nephrectomy remains the most common treatment method, laparoscopic, and to a lesser degree partial nephrectomy, are feasible in well selected patients.

Xanthogranulomatous pyelonephritis - A diagnostic and therapeutic dilemma.

Xanthogranulomatous pyelonephritis (XGP) is a rare variant of chronic pyelonephritis, occurring in the setting of obstructive uropathy and recurrent urinary tract infections (UTIs). It is difficult to diagnose as it can be asymptomatic until late-stage disease. Localized symptoms such as flank pain and dysuria may be attributed to nephrolithiasis or UTIs without prompting need for further workup. Extrarenal manifestations, most notably fistula formation, may present distal to the kidney and not be readily attributed to a renal pathology. The only known definitive therapy is nephrectomy. A delay in diagnosis can lead to fulminant complications or a more technically difficult nephrectomy. We present three cases of XGP, which serve to highlight the possibility of earlier diagnosis and resultant management options, including the potential for nephron-saving strategies. Early clinical and radiologic suspicion through awareness of risk factors may play an important role in preventing disease progression, avoiding late-stage complications, and improving treatment outcomes.

Xanthogranulomatous pyelonephritis: a review and meta-analysis with a focus on management.

PURPOSE: Xanthogranulomatous pyelonephritis (XGP) is a rare form of pyelonephritis more commonly seen in females and diabetics. Frequently associated with renal tract calculi, it is often difficult to diagnose, as it can clinically and radiologically mimic other disorders. Most cases are treated with antibiotics and nephrectomy. The aim of our review is to summarise and analyse the current evidence focusing on management. METHODS: A literature search was conducted to identify papers relating to xanthogranulomatous pyelonephritis in adults. Studies containing ten or more patients with XGP were included for descriptive analysis, and a meta-analyses of cohort studies conducted comparing open and minimally invasive nephrectomy undertaken. Other papers were included for narrative review. RESULTS: 52 studies were identified, 20 were included for narrative review and 32 retrospective observational studies containing 868 patients were included for descriptive analysis. 99.8% of patients underwent nephrectomy, about one-third laparoscopically. The most commonly cultured organisms were Escherichia coli and Proteus mirabilis. 60% of patients, where reported, underwent preoperative drainage. Seven studies containing 211 patients were included for meta-analysis which found that postoperative complications, length of stay and transfusion requirements were all significantly reduced in those who underwent minimally invasive surgery. CONCLUSION: The mainstay management of XGP is antibiotic therapy and nephrectomy. Some studies highlight a role for preoperative upper urinary tract drainage, but evidence supporting this is limited. We present the first meta-analyses examining operative approach for patients undergoing nephrectomy for XGP. Though limited by the data available, our meta-analysis indicates minimally invasive nephrectomy for XGP provides better postoperative outcomes.

Xanthogranulomatous pyelonephritis in a pediatric patient.

INTRODUCTION: Xanthogranulomatous pyelonephritis consists of a chronic infectious and inflammatory process of the renal parenchyma, a variant of chronic obstructive pyelonephritis. It is more prevalent in middle-aged adults, rare in pediatric patients, with less than 300 cases reported in children worldwide. REPORT: Preschooler, aged 2 years and 11 months, male, with 2 months of abdominal distention, increased temperature and intense pallor, associated with microcytic anemia refractory to the use of ferrous sulfate. 1 week before, he had a bulging in his left flank and a hard palpable mass there. Imaging exams (ultrasound and tomography) revealed an overall enlargement of the left kidney, destruction of the renal parenchyma and intense calyceal dilation, forming the "bear's paw" sign, with a staghorn calculus in the pelvis. He underwent treatment with antibiotic therapy and total nephrectomy, with a specimen sent for pathological examination. DISCUSSION: a disease of uncertain incidence in the pediatric age group, xanthogranulomatous pyelonephritis is more prevalent in male children and affects mainly the left kidney, being frequently associated with the presence of stones. Clinically, it has nonspecific symptoms, the most common being abdominal distension and asthenia. Laboratory exams shows microcytic, leukocytosis, thrombocytosis and increased inflammation, pyuria, hematuria and proteinuria, in addition to bacterial growth in urine culture. The diagnosis is anatomopathological, but it can be hinted by contrasted CT scan, with the classical sign of the "bear's paw". Treatment may include nephrectomy and broad-spectrum antibiotic therapy.

Xanthogranulomatous pyelonephritis due to Aspergillus in a non-diabetic older patient.

Xanthogranulomatous pyelonephritis is a rare condition characterised by destructive granulomatous inflammation of renal parenchyma. Primary renal Aspergillosis has been reported in patients with immunocompromised states such as diabetes, retroviral disease, organ transplant recipients, etc. We present a unique case of an older adult in his early 60s, presenting with fever and left flank pain with renal angle tenderness, diagnosed with primary renal aspergillosis with xanthogranulomatous pyelonephritis. These symptoms resolved with a long duration of antifungal (itraconazole) therapy and nephrectomy. The unique features are the development of fungal pyelonephritis in the absence of any immunocompromising conditions and the development of xanthogranulomatous changes with no risk factors.

Malakoplakia and xanthogranulomatous pyelonephritis treated with nephrectomy: A case report.

RATIONALE: Malakoplakia and xanthogranulomatous pyelonephritis are chronic inflammatory conditions of the kidney characterized by the infiltration of inflammatory cells. PATIENT CONCERNS: An 82-year-old female patient had a history of hypertension, type 2 diabetes mellitus, dyslipidemia, and end-stage renal disease under hemodialysis. She was admitted repeatedly 4 times within 4 months due to urosepsis. DIAGNOSIS: The enlarged right kidney with a low-density lesion at the right middle calyx, and a well-enhanced ureter were noted on the computed tomography scan. Therefore, xanthogranulomatous inflammation was suspected. Semi-rigid ureteroscopy with biopsy was performed, and xanthogranulomatous inflammation of the ureter was confirmed on the pathology report. INTERVENTIONS: After right open radical nephrectomy was performed, the final pathology report revealed malakoplakia with xanthogranulomatous pyelonephritis. OUTCOMES: After the surgery, she has no longer suffered from urosepsis for 8 months, and there were no adverse event or recurrence noted. LESSONS: With this case report, we aim to emphasize that these 2 diseases are not mutually exclusive, but they may exist simultaneously in the same patient.

Horseshoe Kidney Complicated by Xanthogranulomatous Pyelonephritis in a Young Girl: A Case Report and Review of the Literature.

The cases of horseshoe kidney presented by xanthogranulomatous pyelonephritis are very rare. In this study, the case of XGP developing in HSK in a young female patient was presented due to its rare incidence and the previously reported cases were reviewed, as well. The patient, who has end-stage renal disease and was under treatment, admitted to the clinic for preemptive kidney transplantation. Bilateral open en bloc nephrectomy was performed before the kidney transplantation. The histopathological examination of the specimen was reported as XGP. Eight months later, living-donor organ transplantation was performed to the patient with the kidney obtained from her father. XGP can present as a complication of HSK. Moreover, HSK may rarely be manifested by end-stage renal disease in young patients. In such cases, who would undergo kidney transplantation, it is important to examine the HSK in detail and perform bilateral nephrectomy to prevent complications after transplantation.

Xanthogranulomatous pyelonephritis: an overview and management guide for clinicians.

Xanthogranulomatous pyelonephritis is a rare and chronic form of pyelonephritis. Patients can present with an array of signs and symptoms including flank pain, fever and weight loss. The insidious nature of its clinical presentation means that it can mimic a neoplastic process. Kidney stone disease, diabetes and female gender are the most common associated factors. Early diagnosis can be difficult, but is vital to avoid sequelae such as abscess formation and involvement of surrounding structures. Management requires a multidisciplinary approach. Definitive resolution can only be achieved through nephrectomy. This article provides an overview and guide to diagnosis, investigation and management.

[The importance of timely and safe care. Report of one case]. / La importancia de la evidencia y de la adherencia a los protocolos clínicos en bienestar de los pacientes. Caso clínico de morbimortalidad.

We report a 32-year-old woman with chronic kidney disease on hemodialysis undergoing a nephrectomy for left xanthogranulomatous pyelonephritis with a coralliform calculus and septic shock. Her clinical evolution was torpid, subfebrile, with persistent elevation of inflammatory parameters and with the finding of intra-abdominal collections interpreted as post-surgical. Finally faced with microbiological evidence of infection of the collections, the patient was operated and tended to improve. Subsequently, she underwent a difficult mechanical ventilation weaning, identifying the abrupt discontinuation of benzodiazepines as a contributing factor to agitation. We report this patient for educational purposes and to reinforce some quality-of-care concepts such as safety and opportunity of healthcare.

Xanthogranulomatous Pyelonephritis with Pyonephrosis and Renal Abscess in a Young Adult: A Consequence of Neglected Urinary Tract Infection Leading to Nephrectomy.

Xanthogranulomatous pyelonephritis (XGP) is a rare form of chronic pyelonephritis, which is challenging to diagnose because its clinical presentation mimics other entities and is commonly associated with a history of urinary tract obstruction. We report a case of XGP in a young adult without nephrolithiasis and urinary tract obstruction. A 23-year-old woman presented with intermittent abdominal pain in the right upper quadrant persisting for the last ten months. The pain was dull, poorly localized, and started spreading to the right back, right shoulder, and right thigh in the last three months. Other complaints included fever, chills, pain during urination, and nausea. The patient had a history of infrequent urination, recurrent urinary tract infections (UTIs), and a low fluid intake. A physical examination revealed that the patient had right upper quadrant abdominal tenderness and right costovertebral angle tenderness. Laboratory findings showed leukocytosis and neutrophilia. The radiological examination revealed a round mass in the superior pole of the right kidney with mixed cystic and solid components, and a well-defined margin. It further enlarged from 4.5 cm to 10.6 cm in diameter in three months. The urologist performed a total right nephrectomy. The histopathological examination showed XGP with renal abscess. Proteus mirabilis was identified from the pus specimen culture. XGP should be considered in the diagnosis of patients having chronic UTI presented with or without the findings of urinary tract obstruction.

Long-Term Antibiotic Treatment Prior to Laparoscopic Nephrectomy for Xanthogranulomatous Pyelonephritis Improves Postoperative Outcomes: Results from a Multicenter Study.

PURPOSE: Xanthogranulomatous pyelonephritis is a destructive bacterial infection typically necessitating nephrectomy. We hypothesized that long-term preoperative antibiotics would facilitate laparoscopic nephrectomy by reducing the renal inflammation. MATERIALS AND METHODS: We reviewed the records of all patients with histologically confirmed xanthogranulomatous pyelonephritis at 3 University of California institutions between 2005 and 2018. Patients were stratified by antibiotic treatment duration and surgical approach. Patients treated with long-term preoperative antibiotics (28 days or more of continuous treatment until surgery) were compared to patients treated with short-term antibiotics (less than 28 days) and those who only received single-dose prophylactic antibiotics before surgery. Patient demographics and operative outcomes were analyzed. Complications were assigned by Clavien-Dindo classification. RESULTS: Among the 61 patients, 51 (84%) were female and mean age was 50 years. There were 21 (34%) open procedures and 40 (66%) laparoscopic procedures. Median duration of antibiotic treatment was 5 days in those who received a short-term treatment and 87 days in those who received long-term treatment. Eleven patients received only prophylactic single-dose antibiotics. Using multivariate analysis among patients undergoing laparoscopic nephrectomy, controlling for preoperative drainage, long-term antibiotics resulted in a 6.5-day shorter length of stay (p=0.023) and less overall as well as milder postoperative complications (p <0.001). CONCLUSIONS: Greater than or equal to 4 weeks of preoperative antibiotics before laparoscopic nephrectomy for xanthogranulomatous pyelonephritis was associated with shorter length of stay and fewer, less severe postoperative complications.

Xanthogranulomatous pyelonephritis: a comparison of open and minimally-invasive surgical approaches.

To compare perioperative outcomes between patients undergoing minimally-invasive (MIS) and open surgical approaches for the treatment of Xanthogranulomatous Pyelonephritis (XGP). Between 2007 and 2017 we retrospectively identified 40 patients undergoing nephrectomy at our institution for pathologically confirmed XGP. Patients whose operations were ultimately completed with open technique were analyzed with the open cohort, whereas patients whose operations were completed in entirety using any laparoscopic approach were analyzed with the MIS group. Twenty-three patients were analyzed in the open cohort, compared to seventeen in the MIS group. Three patients in the open cohort were converted intraoperatively from MIS to open approach. Compared to the open group, the MIS group less often had an abscess on preoperative CT (11.8% vs 54.5%; p = 0.006). The MIS group also had lower intraoperative blood loss (100 vs 400 mL; p < 0.001), lower rate of blood transfusion (0% vs 45.5%; p = 0.002), lower postoperative intensive care admission (0% vs 34.8%; p = 0.013), and shorter hospital stay (4 vs 7 days; p = 0.013). However, there was no significant difference in high-grade complications between these groups (5.9% vs 34.8%; p = 0.054). Preoperative CT scan may be an important factor when considering operative approach for treatment of XGP. Patients who are able to undergo MIS approach have less blood loss, shorter hospitalization, and are less likely to require intensive care admission, which may be related to the disease process, the surgical technique, or both.